Which versions of CloakBrowser cloakserve are affected by EUVD-2026-33724?

CloakBrowser deployments using the vulnerable cloakserve component (pip package cloakbrowser ≤0.3.27) face unaccountable file system deletion by any network user, risking operational continuity and…. A patch is available.

How to fix or mitigate EUVD-2026-33724?

Within 24 hours: identify all systems running cloakbrowser and verify which have cloakserve endpoints exposed to network access. Within 7 days: upgrade cloakbrowser to the patched version released by the vendor per the security advisory. Within 30 days: conduct file system integrity verification across all affected systems and review service logs for access anomalies during the vulnerability window.

CloakBrowser cloakserve EUVD-2026-33724

Q: What is the CVSS score of EUVD-2026-33724?

EUVD-2026-33724 has a CVSS 4.0 base score of 8.8 (High). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.1%.

| CVE-2026-45727 HIGH

Path Traversal (CWE-22)

2026-05-18 https://github.com/CloakHQ/CloakBrowser

GHSA-mf33-gv72-w2h5

Path Traversal Google Chrome

8.8

CVSS 4.0 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

8.8 HIGH

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Lifecycle Timeline

Analysis Updated

Jun 01, 2026 - 19:28 vuln.today

v3 (cvss_changed)

Analysis Updated

Jun 01, 2026 - 19:28 vuln.today

v2 (cvss_changed)

Re-analysis Queued

Jun 01, 2026 - 19:22 vuln.today

cvss_changed

CVSS changed

Jun 01, 2026 - 19:22 NVD

8.8 (HIGH)

Source Code Evidence Fetched

May 18, 2026 - 18:30 vuln.today

Analysis Generated

May 18, 2026 - 18:30 vuln.today

DescriptionGitHub Advisory

The cloakserve CDP multiplexer uses the user-supplied fingerprint query parameter directly as a filesystem path component when creating Chrome profile directories. An unauthenticated attacker who can reach the cloakserve port can supply a crafted fingerprint value containing path traversal sequences to resolve user_data_dir outside the configured data_dir. When Chrome fails to start or the process is cleaned up, shutil.rmtree() deletes the traversed path, resulting in arbitrary directory deletion.

Additionally, cloakserve bound to 0.0.0.0 by default, making it network-exposed.

Impact

An attacker with network access to the cloakserve port can delete arbitrary directories accessible to the service user.

Patches

Fixed in v0.3.28.

Mitigations

Upgrade to v0.3.28 or later
Restrict network access to the cloakserve port

AnalysisAI

Arbitrary directory deletion in CloakBrowser's cloakserve CDP multiplexer (pip package cloakbrowser <= 0.3.27) allows unauthenticated network attackers to delete directories accessible to the service user by supplying path traversal sequences in the fingerprint query parameter. The service binds to 0.0.0.0 by default, dramatically widening exposure, and no public exploit identified at time of analysis though the vulnerability is trivially reproducible from the published advisory.

Technical ContextAI

cloakserve is a Chrome DevTools Protocol (CDP) multiplexer shipped in the CloakBrowser Python package (pkg:pip/cloakbrowser). It spawns Chrome instances and isolates them via per-session profile directories rooted under a configured data_dir. The root cause is CWE-22 (Improper Limitation of a Pathname to a Restricted Directory): the fingerprint query parameter is concatenated/joined into the user_data_dir path without canonicalization or containment checks, so sequences such as ../../ resolve outside data_dir. When Chrome subsequently fails to start or the session is torn down, the cleanup path invokes Python's shutil.rmtree() against the attacker-controlled resolved path, recursively deleting whatever the service's user can write to. Compounding the bug, the listener binds to 0.0.0.0 by default rather than loopback, so any reachable host on the network can trigger the sink.

RemediationAI

Vendor-released patch: 0.3.28 - upgrade the cloakbrowser PyPI package to 0.3.28 or later (pip install --upgrade 'cloakbrowser>=0.3.28') as the primary remediation, per advisory GHSA-mf33-gv72-w2h5 (https://github.com/CloakHQ/CloakBrowser/security/advisories/GHSA-mf33-gv72-w2h5). If immediate patching is not possible, restrict network access to the cloakserve port via host firewall rules (iptables/nftables/Windows Firewall) or by placing the service behind a reverse proxy that enforces source-IP allowlisting; explicitly bind cloakserve to 127.0.0.1 instead of 0.0.0.0 where the launch configuration permits, accepting that remote CDP clients will then need to be tunneled (e.g., SSH port-forward) which adds operator friction. Run the service under a dedicated low-privilege user whose filesystem write scope is limited to data_dir so that any successful traversal cannot reach sensitive system directories or other users' data, noting this is mitigation rather than fix and does not prevent destruction of the service's own state.